Exposure on open shore determined by local changes in wave length, height and frequency. Significant wave height = the average height of the highest one third of waves and is dependent upon the distance of open sea water over which wind may blow to generate waves (the fetch) and the strength and incidence of winds, and topography; generally significant wave height is <1.2m but can be up to 3m around UK coast.
Benchmark:
A change in nearshore significant wave height >3% for one year.
Examples:
Anthropogenic sources of this pressure include artificial reefs, breakwaters, barrages, wrecks that can directly influence wave action or activities that may locally affect the incidence of winds, e.g. a dense network of wind turbines may have the potential to influence wave exposure, depending upon their location relative to the coastline. Seaweed harvesting and beach replenishment may also affect wave exposure. Further research is required on the correlation between significant wave height and wave exposure scales.